how do i compile/link test cases (googleTest) using cmake to the code bundled up in shared library?

Question

My project is organized like this:

• cpp
  • main.cpp (calls code from dataStructures/ and common/)
  • CMakeLists.txt (topmost CMakeLists file)
  • build
  • test
    • main.cpp
    • CMakeLists.txt
    • common
      • CMakeLists.txt
      • include
      • src
    • googletest
    • build
  • common
    • CMakeLists.txt (should be responsible for building common shared library)
    • include
      • utils.h
    • src
      • utils.cpp
    • build

build\ directories contain the built target. The actual code can be seen here: https://github.com/brainydexter/PublicCode/tree/master/cpp

I'm able to build shared libraries for the actual code ( like common). Now, I'd like to test it using GoogleTest. So, I created a test directory and put the test code in there (what I have in the repo is just a sample, more like hello world to get the build system up and working. I will be adding more test cases later on).

I need some help in triggering the tests from the topmost CMakeLists.txt. I'm not sure how to do this. In test, CMakeLists.txt looks like this:

cmake_minimum_required(VERSION 3.1.2)

add_subdirectory(googletest/googletest)
include_directories(googletest/googletest/include)

add_subdirectory(common)

enable_testing()

add_executable(testCpp main.cpp)
target_link_libraries(testCpp gtest gtest_main )

Do I need to add anything else to enable tests in test/common ?

test/common/CMakeLists.txt:

file(GLOB SOURCES "src/*.cpp")

add_executable(testCommon ${SOURCES})

target_link_libraries(testCommon cppCommon)

I'm not sure if the target should be executable here or a library that the google test framework can consume ? I'd appreciate any help on this.

Answer 1

You may find the FindGTest module helpful. Since the location of gtest is fixed, you can do something along these lines to find it:

set (GTEST_ROOT ${CMAKE_SOURCE_DIR}/googletest)
find_package (GTest required)

As for whether you need an executable, this module defines the GTEST_MAIN_LIBRARIES variable, so that when you link your tests, you simply need to do:

target_link_libraries(testCommon ${GTEST_MAIN_LIBRARIES})

The resulting binary will use the default gtest main function.